With hundreds of process steps and expensive equipment, queue time control is critical to the economic viability of an integrated circuit device manufacturing facility. As wafers are processed through the facility, they must often be protected from the ambient environment. If, following completion of processing in one tool, the next tool is not immediately available, wafers must often be stored in a protected environment. The wafers can be stored within the tool in which they have completed processing, but this forces the tool to become idle. Alternatively, the wafers can be stored in an environmentally controlled storage rack. Such storage racks are additional structures that take up valuable plant floor space and require additional capital investment.